Present day concern for the environment and the safety of the public is ever increasing. This is especially true in the handling of pollutants such as toxic chemicals, waste and petroleum products such as gasoline, fuel oil, etc., and others. This concern is exemplified by the emergence of devices which detect leaks in the structures containing such material as illustrated in U.S. Pat. Nos. 4,305,068 issued Dec. 8, 1981; 3,995,472 issued Dec. 7, 1976; and 3,564,526 issued Feb. 16, 1971.
A significant problem in the handling of potential pollutants aside from rupturing or leaking of the containers is overflow or spillage during the filling (or emptying) of the container. This is particularly critical in situations where the spillage is absorbed by the ground and finds its way into the ground water table, contaminating the water supply. While spillage or overflow can occur during the filing of elevated as well as underground containers, due to the proximity of the soil underground tanks are of particular concern. A frequent example of this is when a chemical containing tank is overfilled or upon delivery of fuel etc., by a truck, the operator fails to drain the delivery hose before disconnecting it from the fill pipe, the removal of which from the fill pipe causes the material in the hose to spill out. Not only does such spillage pose a great danger to the environment, but in addition, if the container is equipped with one of the leak detector sets as set forth in the aforenoted patents, such spillage could activate the detector thereby falsely indicating a leak. Such a false alarm would lead not only to great inconvenience but expense as well. Note that due to the potential widespread application, i.e., commercial, municipal, and residential, a device for controlling pollutants in this regard should be relatively simple and inexpensive and readily adaptable for a variety of applications.